"""
users = []
for i in range(0, 3):
    name = input("请输入用户名和密码：")
    users.append(name)
print(users)


username = input("请输入用户名：")
password = input("请输入密码：")
for item in users:
    result = item.split(",")
    user = result[0]
    pwd = result[1]
    if user == username and pwd == password:
        print("欢迎登陆")
        break
"""
"""
users=["sao","yuan","hh","huiyou"]
users.insert(2,"hehe")
print(users)
"""
"""
users=["sao","yuan","hh","sao","huiyou"]
users.remove("sao")
print(users)
"""
# users=["sao","yuan","hh","sao","huiyou"]
# users.pop()
# print(users)
users=["sao","yuan","hh","sao","huiyou"]
users[2]="66"
users[1][1]=2
print(users[1][1])
str